The present invention relates to N-substituted perfluoroalkylated pyrrolidines, reaction products thereof and the use of these reaction products as specialty surfactants, as oil- and grease-proofing agents for paper, textiles and hard surfaces such as masonry and wood.
Perfluoroalkylated polymers which are used for treatment of textile and paper products to impart water, oil and grease repellency are almost exclusively derived from RF-substituted acrylates or methacrylates, where RF represents a perfluorinated alkyl or alkenyl moiety. Certain RF-acrylamide derivatives, although described in the literature, have not found a use in the market because of their uneconomical synthesis cost. A novel RF-acrylamide has now been found which is easily prepared in high yield from readily available starting materials, i.e. diallylamine, an RF-iodide and a difunctional acryloyl derivative, preferably 3-chloropropanoic acid chloride. Reaction products of this RF-acrylamide have diverse uses.
U.S. Pat. No. 3,535,381 describes the synthesis of RF-substituted amines and (meth)acryl-amides thereof by reaction of RF-ethylene with a primary amine with elimination of hydrofluoric acid, followed by reaction with methacroyl chloride. The yield of RF-amine based on the RF-iodide is about 60%. U.S. Pat. No. 3,996,281 describes the synthesis of RF-amines and derived (meth)acrylates from RF-epoxides or RF-chlorohydrins by reaction with primary or secondary amines. The necessity of preparing an RF-epoxide first makes this approach very impractical. Other previously described RF-acrylamides are described in JP 10139747 A2, for example RF-ethylacrylamide synthesized from acryloyl chloride and 1,1-dihydro-heptafluorobutylamine. EP-A 177122 describes an RF-substituted urethane derived from acryloyl isocyanate.
U.S. Pat. No. 3,996,281 describes N,N-di-RF-acrylamides derived from an RF-epoxide, an amine and acryloyl chloride. U.S. Pat. No. 3,763,225 describes an RF-acrylamide derived by reaction of RF-iodide with a primary amine and amidification with acyloyl chloride in pyridine. JP 03261749 describes an N-RF-ethyl-N-allyl diacrylamide prepared from RF-ethyl iodide by reaction with allylamine and acryloyl chloride.
The free radical-induced addition of perfluoroalkyl iodides to N,N-diallyl derivatives and subsequent formation of pyrrolidines by ring closure is well documented. Brace, in J. Polymer Science, Part A-1, 8, 2091 (1970) describes the synthesis of 3-(perfluoroalkyl)methyl-4-methylenepyrrolidine of the formula I 
by addition of RF-iodide to diallylcyanamide and subsequent hydrolysis; large amounts of the corresponding pyrrolidine amide are formed as a by-product. In the case of diallylamine itself, Brace (J. Org. Chem. 36, 3187 (1971)) found that the intermediate RF-iodide adduct formed a polymeric RF-amino compound by substitution; the desired RF-pyrrolidine amine of the formula I was not obtained.
The N-benzoyl, N-acetyl and N-trifluoroacetyl, N-carbonitrile, N-propionitrile and N-carboxamide derivatives of 3-(perfluoroalkylmethyl)4-methylenepyrrolidine are known from Brace, J. Org. Chem. 36, 3187 (1971), and maleic acid amide copolymers are known from U.S. Pat. No. 5,427,859. Each of these products however is made by reacting the N-substituted diallylamine with RF-iodide, and it is often almost impossible to remove the eliminated iodide salts from the final product, especially if the product is water soluble.
It is an object of the present invention to provide a convenient high yield synthesis of 3-(perfluoroalkyl)methyl4-methylenepyrrolidine. It is a further object of the present invention to provide fluorinated derivatives thereof, such as amides, ureas, ethers and urethanes, by reaction of 3-(perfluoroalkyl)methylmethylenepyrrolidine with amino-reactive compounds such as carboxylic acids, acid chlorides, anhydrides, oxiranes, isocyanates, halo-alkanes, ureas and (meth)acrylates or other vinyl compounds, which fluorinated derivatives are substantially free of iodide salts and which are useful as specialty surfactants and as oil proofing agents for paper and textiles.
It is a further object of the present invention to provide a novel monomer, 1-(meth)acryloyl-3-(perfluoroalkyl)methyl4-methylenepyrrolidine of the formula II 
wherein R is hydrogen or methyl and RF is a perfluorinated alkyl or alkenyl moiety and a method for its synthesis from diallylamine, RF-iodide and a (meth)acryloyl derivative using a novel process for the addition of the RF-iodide to the allylic double bond.
It is a further object of the present invention to provide polymers derived from 1-(meth)acryloyl-3-(perfluoroalkyl)methyl-4-methylenepyrrolidine which are useful to impart water, oil and grease repellency to substrates such as wood, paper, textiles, metal, glass or masonry.
The inventive RF-(meth)acrylamides can readily be copolymerized with other vinyl monomers, such as (meth)acrylates, (meth)acrylamides, styrene or vinyl ethers or -esters. The hydrolytic stability of polymers based on tertiary acrylamides gives them a special advantage over the more commonly used (meth)acrylates, because it allows the synthesis of anionic water-dispersible polymers which need to be stable at alkaline pH.
The present invention relates to novel RF-pyrrolidines of the formula III 
in which
RF is a monovalent perfluorinated alkyl or alkenyl, linear or branched organic radical having four to twenty fully fluorinated carbon atoms,
B is a direct bond, xe2x80x94C(xe2x95x90O)xe2x80x94 or xe2x80x94C(xe2x95x90O)xe2x80x94Nxe2x80x94,
q is an integer from 1 to 10 in which,
when q is 1,
Q is a monovalent organic radical with 2 to 200 carbon atoms and which can contain one or more unsaturated groups and is optionally interrupted by one or more xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 linkages or tert. amino groups, and which is unsubstituted or substituted by one or more hydroxyl, tert. amino, amide, RF, xe2x80x94P(xe2x95x90O)(OH)2, xe2x80x94SO3H or xe2x80x94COOH groups, or is also NH2 if B is xe2x80x94C(xe2x95x90O)xe2x80x94, and, when q is greater than 1,
Q is a di- or polyvalent organic radical with 2 to 200 carbon atoms which can be interrupted by one or more xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94 linkages, amide or tert. amino groups, and which is unsubstituted or substituted by one or more hydroxyl, tert. amino, amide or carboxyl groups; xe2x80x94C(xe2x95x90O)xe2x80x94 or a di- or triradical derived from cyanuric chloride,
with the proviso that if Q is xe2x80x94C(xe2x95x90O)xe2x80x94, B is a direct bond,
and wherein any amino groups are optionally partially or fully salinized, quatemized or in the form of the corresponding N-oxides.
Preferably RF is saturated and contains 4-12 carbon atoms, is fully fluorinated and contains at least one terminal perfluoromethyl group; most preferably RF is saturated and contains 6-10 fully fluorinated carbon atoms.
Preferably q is 1 or 2.
Preferred are compounds of the formula III wherein q is 1 and B-Q is xe2x80x94(CH2)1-3COOH; xe2x80x94CH2xe2x80x94C(xe2x95x90O)NH2; xe2x80x94C(xe2x95x90O)xe2x80x94CRxe2x95x90CH2; xe2x80x94C(xe2x95x90O)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(CH2)2-3xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94CHxe2x95x90CHxe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94C(xe2x95x90CH2)xe2x80x94CH2xe2x80x94COOH and xe2x80x94C(xe2x95x90O)xe2x80x94CH2xe2x80x94C(xe2x95x90CH2)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(C6H4)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(C6H8)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(C6H5RF)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(C7H6)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(C8H8)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)(CH2)8CHxe2x95x90CH2; xe2x80x94CH2xe2x80x94CHOHxe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94CHxe2x95x90CH2; xe2x80x94C(xe2x95x90O)CH3; xe2x80x94CH2CH2N(CH3)2; xe2x80x94Cxe2x80x94CH2CH2CH2N(CH3)2; xe2x80x94CH2xe2x80x94CH(OH)xe2x80x94CH2xe2x80x94N(CH3)3+; xe2x80x94CH2xe2x80x94CHOHxe2x80x94CH2xe2x80x94Oxe2x80x94(CH2CHRxe2x80x94O)mR1; xe2x80x94P(xe2x95x90O)(OH)2 or xe2x80x94SO3H, in which R is hydrogen or methyl, m is a number from 1 to 20 and R1 is hydrogen, an alkyl group with 1 to 20 carbon atoms, or a phenyl group substituted by p-octyl- or p-nonyl, or SO3H.
R and R1 are preferably hydrogen. Preferably m is a number from 1 to 10.
Most preferred are compounds of the formula III wherein q is 1 and B-Q is xe2x80x94C(xe2x95x90O)xe2x80x94CRxe2x95x90CH2; xe2x80x94CH2xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(CH2)2xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(C6H4)xe2x80x94COOH; xe2x80x94C(xe2x95x90O)xe2x80x94(C6H5RF)xe2x80x94COOH or xe2x80x94C(xe2x95x90O)xe2x80x94(C6H8)xe2x80x94COOH wherein R is hydrogen or methyl. Especially preferred are 1-(meth)acryloyl-3(perfluoroalkyl)methyl4-methylene compounds of the formula II 
Also preferred are compounds of the formula III wherein q is 2, B is a direct bond and Q is xe2x80x94CH2xe2x80x94CHOHxe2x80x94CH2xe2x80x94Oxe2x80x94(CH2 CHRxe2x80x94O)mxe2x80x94((CH2xe2x80x94CHR2xe2x80x94O)nxe2x80x94(CH2xe2x80x94CHR3xe2x80x94O)l)zxe2x80x94CH2xe2x80x94CHOHxe2x80x94CH2xe2x80x94; xe2x80x94CH2CH2xe2x80x94; or xe2x80x94CH2xe2x80x94CHOHxe2x80x94CH2xe2x80x94; wherein R, R2 and R3 are independently of each other hydrogen or methyl, m, n and l are a number from 1 to 20 and z is zero or 1; with the proviso that if R2 is hydrogen, R and R3 are methyl and vice versa; or
xe2x80x94CH2 CH2xe2x80x94C(xe2x95x90O)xe2x80x94NHxe2x80x94CH2xe2x80x94NHxe2x80x94C(xe2x95x90O)xe2x80x94CH2CH2xe2x80x94; or where B is xe2x80x94C(xe2x95x90O)xe2x80x94NHxe2x80x94 and Q is the diradical hydrocarbon residue of p- or m-toluene diisocyanate, isophorone diisocyanate, 3,3,4(3,4,4)trimethylhexane-1,6diisocyanate or hexane-1,6diisocyanate; or where B is xe2x80x94C(xe2x95x90O)xe2x80x94 and Q is xe2x80x94(C6H2)(xe2x80x94COOH)2)xe2x80x94, xe2x80x94(C13H6O)(xe2x80x94COOH)2)xe2x80x94, or is C2-C10alkenylene or xe2x80x94C6-C10arylene.
Most preferred are compounds of the formula III where q is 2 and B-Q is xe2x80x94CH2xe2x80x94CHOHxe2x80x94CH2; xe2x80x94C(xe2x95x90O)xe2x80x94CH2CH2xe2x80x94C(xe2x95x90O)xe2x80x94 or xe2x80x94C(xe2x95x90O)xe2x80x94(xe2x80x94C6H2(xe2x80x94COOH)2)xe2x80x94C(xe2x95x90O)xe2x80x94.
Compounds which are 3-(perfluoroalkyl)methyl-4-methylenepyrrolidines of the formula I 
are useful as intermediates to prepare compounds of the formula III. The synthesis of a compound of the formula I is preferably carried out stepwise by reaction of diallylamine with an equivalent amount of RF-iodide in an aqueous medium at temperatures of from 5 to 50xc2x0 C., using sodium dithionite as initiator, followed by elimination of Hl with a base, to form a 3-(perfluoroalkyl)methyl-4-methylenepyrrolidine of the formula I.
By adjusting the reaction mixture to an alkaline pH, this intermediate can be washed substantially free of iodide salts. This leads to an iodide-free end product in the subsequent step.
To prepare a compound of the formula III, the 3-(perfluoroalkyl)methyl-4-methylenepyrrolidine intermediate of the formula I is reacted with an anhydride such as oxalic-, glutaric-, alkenyl-succinic-, succinic-, tetrahydrophthalic-, norbornene-; methendic-, maleic-, trimellitic or itaconic anhydride, to form the corresponding amic-acid;
with a dianhydride such as pyromellitic anhydride or benzophenone-tetracarboxylic acid dianhydride to form the corresponding di-amic acid;
with an acyl halide such as benzoyl chloride or acetyl chloride or with a diacyl halide such as oxalylchloride, or an alkyl ester such as ethyl undecylenate or a dialkyl ester such as dimethyl succinate, to form the corresponding amides or diamides;
with a halogenated organic compound such as 1,4-dichloromethylbenzene, chloroacetic acid, chloropropionic acid or chloroacetamide to form the corresponding tertiary amine or tertiary amine-acid;
with a diisocyanate such as isophorone diisocyanate, toluene diisocyanate, 1,6-diisocyanatohexane or 1,6-diisocyanato-3,3,4(3,4,4)-trimethylhexane to form the corresponding diurethane;
with an oxirane or a polyoxirane compound such as epichlorohydrin, ethylene oxide, propylene oxide, cyclohexane oxide, styrene oxide, allyl glycidyl ether, and the diglycidyl ether of bisphenol A, bisphenol F or 1,4-butanediol, to form the corresponding hydroxy-tertiary amino compounds;
or with a phosphoric acid derivative such as POCl3, polyphosphoric acid or sodium metaphosphate to form the corresponding phosphamic acids.
The compounds of formula III can also be made by first preparing N,N-diallyl intermediates either through the reaction of diallylamine with the reactants mentioned above, or by reaction of primary amines Qxe2x80x94(NH2)q with two equivalents of allyl chloride, in either case adding the RF-iodide during the last step. A large variety of primary amines and polyamines can be used to make compounds of formula III in which B is a direct bond and Q is a hydrocarbon residue as defined above. Typical amines are aliphatic, cycloaliphatic and aromatic amines and substituted amines with 1 to 20 carbon atoms such as stearylamine; glycine, lysine and other amino acids; N,N-dimethylpropane-1,3-diamine, p-amino benzoic acid, sulfanilic acid, N,Nxe2x80x2-bis-3-aminopropyl piperazine, ethylendiamine, diethylenetriamine and bis-(3-aminopropyl)ethylenediamine.
The radical Q can itself be RF-substituted if it is derived for example from RF-undecylenic acid, 3-RF-tetrahydrophthalic anhydride or 3-RF-4-iodo-norbornene anhydride. In such cases it is preferable to first react diallylamine with any of the unsaturated precursors - undecylenic acid, tetrahydrophthalic anhydride and/or norbornene anhydridexe2x80x94then to add the RF-iodide last and simultaneously to both types of double bonds in the corresponding diallyl amides. Such compounds of formula (III) in which Q is substituted by an RF-group are another object of this invention.
Compounds of formula III containing tertiary amino groups can, if desired be quatemized with quatemizing agents such as alkyl halides, chloroacetic and chloropropionic acids, benzyl chloride, allyl chloride, chloroacetamide, propiolactone or propanesultone. They can also be oxidized to the corresponding N-oxides with a peroxy compound such as H2O2 or salinized with an inorganic or preferably organic acid. Such compounds are another object of this invention.
The synthesis of the preferred 1-(meth)acryloyl-3-(perfluoroalkyl)methyl-4-methylene compounds of the formula II 
wherein R is hydrogen or methyl and RF is as previously defined can be carried out in various ways. One method entails the addition of RF-iodide to diallylamine, forming a 3-(perfluoroalkyl) methyl-4-methylenepyrrolidine of the formula I, followed by reaction with (meth)acryloyl chloride, (meth)acrylic acid or a (meth)acrylic acid ester and finally elimination of Hl with a base. Invariably a large amount of by-product is formed as a result of Michael addition of the pyrrolidine to the acrylic double bond. In the case of the acrylamide, this problem can be circumvented by using 3-chloropropionyl chloride (CPC) to form the amide, followed by elimination of HCl with a base to form the corresponding acrylamide.
An alternative and preferred method of preparing a 1-acryloyl-3-(perfluoroalkyl)methyl-4-methylenepyrrolidine of the formula IIa 
comprises first reacting 3-chloropropionyl chloride (CPC) with diallylamine to form N,N-diallyl-3-chloropropaneamide, then reacting this product with RF-iodide followed by eliminating HCl and Hl by dehydrohalogenating with a base such as an alkali metal hydroxide. The product of the formula IIa is then washed with water followed by separating the aqueous layer.
The addition of RF-iodide to the diallylamine moiety is accomplished in an aqueous medium advantageously containing from 5 to 50% by weight of a water-soluble cosolvent such as an alcohol or ketone, to compatibilize both reactant phases. Preferred cosolvents are lower alcohols such as methanol, ethanol, n- and iso-propanol and t-butyl alcohol. A suitable free radical initiator for the addition of RF-iodide is 0.01 to 10 mole %, preferably 0.1 to 5 mole %, based on the RF-iodide of an alkali metal dithionite, preferably sodium or potassium dithionite, preferably in the presence of a water-soluble aldehyde such as formaldehyde or glyoxal or, especially, in the presence of an aldehyde adduct such as hydroxymethane sulfinic acid, sodium salt (the addition product of formaldehyde and sodium dithionite). It is commercially available as the dihydrate from Aldrich Chemical Company. It is also commercially available under the tradename Rongalite. The aldehyde or aldehyde adduct is believed to scavenge bisulfite ions, which would otherwise react with the primary chloride or with the acrylic double bond of 3-chloropropionyl chloride to form surfactant-like molecules by forming an adduct with them.
Suitably the reaction is conducted at temperatures of 0 to 60xc2x0 C.
The addition of RF-iodide to double bonds only in the presence of equivalent amounts of dithionite or Rongalite is known from Huang, Acta Chimica Sinica, 44 488, (1986) and Huang, Chin. J. Chem. (1990), 191, respectively.
U.S. Pat. No. 5,585,517 describes the addition of RF-iodide to allyl alcohol using an azo-type free radical initiator together with an alkali metal bisulfite or dithionite ion, which in this case only serves to reduce any free iodine which would otherwise inhibit the reaction. Copending U.S. patent application Ser. No. 09/234,251 describes the addition of RF-iodide to allylic double bonds at low temperature, using only catalytic amounts of an alkali metal dithionite to create ion-radicals for initiation, with no mention of the presence of an aldehyde. In the present situation, where the end product is an acrylate, the reaction is complicated by the fact that bisulfite ion (the decomposition product of the dithionite) not only easily displaces a primary chloride, but can also add to the acrylic double bond which is formed under the basic conditions required for HCl elimination, in either case forming a very potent RF-sulfonate surfactant as by-product. This reduces the yield of the desired acrylamide product and makes isolation by phase separation very difficult due to excessive foaming and emulsification. This problem is circumvented by the use of an aldehyde or aldehyde adduct to stabilize the alkali metal dithionite. Most preferred is the use of Rongalite, the above-mentioned complex of formaldehyde and sodium dithionite.
An added advantage of Rongalite is that it is more stable than an alkali metal dithionite alone at the low pH required to carry out the RF-iodide addition reaction; at a high pH HCl is eliminated prematurely.
Thus another object of this invention is a process for the addition of RF-iodide to an olefin which comprises reacting an RF-iodide with an olefin in the presence of 0.01 to 10 mole %, preferably 0.1 to 5 mole %, based on the RF-iodide of a combination an alkali metal dithionite and a water-soluble aldehyde or an adduct of an alkali metal dithionite and a water-soluble aldehyde, where RF is as defined above. Preferably the alkali metal dithionite is sodium or potassium dithionite and the water-soluble aldehyde is formaldehyde or glyoxal. The preferred adduct of an alkali metal dithionite and a water-soluble aldehyde is hydroxymethane sulfinic acid, sodium salt, the addition product of formaldehyde and sodium dithionite. Advantageously the reaction is carried out in an aqueous medium containing 5-50% by weight of a water-soluble cosolvent and at temperatures of 0 to 60xc2x0 C.
Preferred bases for the subsequent dehydrohalogenation are alkali metal hydroxides, in particular sodium and potassium hydroxide.
To avoid polymerization during the dehydrohalogenation, it is advisable to carry out the reaction in the presence of a polymerization inhibitor such as phenothiazine, p-methoxyphenol or other conventional inhibitors known in the art.
When the compounds of the present invention are used as grease and oil repellent paper sizing agents, they are applied by methods known per se in amounts which are sufficient to deposit from 0.005 to 0.5% of organically bound fluorine by weight based on the dry paper weight. The compounds of the present invention can be applied either externally in topical applications, for instance in a size press to the surface of paper or cardboard. They can also be applied internally, by adding them to an aqueous pulp together with other wet-end chemicals, as described for instance in U.S. Pat. No. 5,091,550, the disclosure of which is incorporated by reference, and more generally in W. F. Reynolds, xe2x80x9cThe Sizing of Paperxe2x80x9d, TAPPI Press, 1989.
It has been very unexpectedly found that the reaction products of 3(perfluoroalkyl)methyl-4-methylenepyrrolidine with anhydrides and dianhydrides perform as well as the best available polymeric fluorinated compounds as treatments for the grease-repellent paper that is employed in pet-food packaging; no other small fluorinated molecule has given equivalent performance.